Australia's outlaw motorcycle gangs used to have a code by which they prosecuted their bloody turf wars and avoided publicity about their criminal activities: not at home, not at work and not in front of women or children. But on March 22, in the terminal of one of Australia's busiest airports, two of the gangs rewrote the code in blood when one gang member was bashed to death in front of horrified bystanders, women and children included.

The killing was just one of a series of "bikie" murders and shootings in the past few weeks that has sparked widespread fear in Sydney and elsewhere. Police are concerned that a new and more deadly generation of "one-percenters"  as the bikies like to call themselves, because they believe they are part of a tiny group outside the law  has taken over. As a result, the police want stricter laws to allow them to crack down on the gangs. (See pictures of gangs in New Zealand.)

The latest trouble began on Flight 430 to Sydney last Sunday. Aboard the plane was a group of heavily tattooed and muscled men who appeared agitated and were sending text messages from their cell phones, according to other passengers. The men were bikies from two of Australia's most feared gangs  the Comancheros and the Hells Angels, both of which had been in the southern city of Melbourne attending, ironically enough, a so-called peace summit.

As soon as the men deplaned, they began pushing and shoving one another before launching into a wild brawl that raged through Sydney's domestic terminal, bowling over a baby in a stroller and into the secure check-in area, where waiting associates joined in. In front of horrified passengers, one of the brawlers was allegedly knocked to the ground, and with what was described as a sickening "crunch" fatally bashed in the head with a steel post used to mark passenger lines. As the man lay dying in a pool of blood, the mob fled in taxis. One group was picked up by police in Sydney's south; four men have been charged with affray, or group-fighting in a public place that puts bystanders in danger. (See pictures of wildfires devastating Australia.)

The following night, a volley of shots peppered a Sydney home in what police fear was another biker-gang-related incident. Then on Tuesday afternoon, two men, one of whom was a member of the Rebels bikie gang, were shot dead in a suburban home in Australia's capital, Canberra, a town not renowned for violent shooting murders.

Police ruled out a link between the Canberra killing and the airport incident, but investigations into other attacks are continuing. The violence has triggered outrage and calls for harsher penalties as well as criticism of law-enforcement agencies for failing to crack down on the gangs earlier. Prime Minister Kevin Rudd, who was in the U.S. at the time of the attacks, said the behavior was "unacceptable in Australia, absolutely unacceptable." (See pictures of fighting crime in Mexico City.)

The government of New South Wales has established a task force of 75 officers to track the bike gangs. It is also pondering the introduction of new laws to declare illegal membership in or association with particular clubs. "These groups are behaving like wild animals  uncivilized and with no regard for our community. If they behave like this, then we have no choice but to hunt them down and deal with them," an angry New South Wales police commissioner, Andrew Scipione, told reporters. Scipione has defended the police record in dealing with gangs. He says that in the past six months, 185 gang members and associates have been charged with 572 offenses, most of them related to violence, drugs and weapons.

But the violence looks unlikely to abate anytime soon. Bikie gang expert and criminologist Arthur Veno, a professor at Monash University in Melbourne, says the step-up in violence is happening because of the rise of Notorious, a younger gang that has muscled in on established gangs' turf in Sydney. "This new gang doesn't have the traditional rules of engagement that the bikies share among themselves," he says. "The war has broadened from the issue of a simple battle over the issue of the drug pyramid. It has now spilled into the long-term affiliations between clubs and has allowed old conflicts to surface." Veno says the gangs had been trying to broker a peace to head off the plans for new laws banning their existence. "[Notorious] have made an outrageous move of hitting people coming from peace talks that could have saved their bacon." (See pictures of Australia rescuing its koalas.)

An Australian Crime Commission report this year revealed that 3,300 outlaw motorcycle-gang members are active in Australia, with 19 of 39 gangs operating in New South Wales. In the lead-up to Sunday's attack, a series of suspected bikie-related crimes had raged across the state capital, Sydney, including a drive-by shooting that occurred just hours before the airport attack that left two men injured and seven homes damaged. In February, the Hells Angels' clubhouse was bombed.

This is not the first time gang-related violence has shocked Australia. In the parking lot of a tavern in western Sydney 25 years ago, the Comancheros and the Bandidos went at each other in a shoot-out that left seven people, including a female bystander, dead and the community stunned. Australians hope those days haven't returned.